It is known in the prior art that altering the body temperature of a patient by means of extracorporeal heating can treat a variety of diseases, such as Hepatitis C and possibly some types of cancer, HIV/AIDS, rheumatoid arthritis and psoriasis. In order to heat the blood in a reasonable amount of time, high flow rates are necessary from the patient's body to a heater and back to the patient.
Centrifugal pumps have been used in prior art systems in order to achieve relatively large flow rates of blood to and from the patient's body. Although the centrifugal pumps can achieve the necessary high flow rates, the centrifugal pumps create relatively large shear forces on the blood resulting in an undesirable amount of hemolysis. Hemolysis is a particular concern with heated blood, since the membranes of the red blood cells are weaker at higher temperatures, and thus the cells are much more prone to rupturing when subjected to shear forces at high temperatures.
Because of the large flow rates of blood to and from the patient, a leak in the system could quickly result in the death of the patient.
The prior art systems also typically involve bulky equipment and are relatively clumsy, resulting in time lags when switching the system from one patient to the next, and increasing the risk of the system being improperly set up.